The police in Rio de Janeiro say a Russian diplomat who was the victim of an attempted robbery near the Olympic Park shot the assailant dead, but the Russian Embassy has denied its employees were involved.

The police say Russia's vice consul, who they identified as a Brazilian native, wrestled with a gunman who was trying to rob him, causing the weapon to go off and killing the criminal.

But the Russian Embassy in Brasilia refuted the police report and said none of their diplomats are armed. It added that all of its employees have "Russian names, which is not the case" in the reported assault.

It was the latest high-profile incident of crime reported in a city where 85,000 police and soldiers have been deployed to keep peace and order during the games.